This invention relates to pumps of the multiplex type. More particularly, but not by way of limitation, this invention relates to a triplex pump of the type in which the pump fluid is precompressed prior to discharge.
In the oil industry it has become common in the past to utilize multiplex pumps designed to deliver pumped fluid at high pressures on the order of 15.000 psi or greater. It has been found that even the slight compressibility of relatively incompressible pumped liquid medium may result in pulsating discharge pressure conditions since a portion of the power intended to accomplish the discharge phase of each pumping cycle is inherently utilized to first compress the liquid medium before it is brought to discharge pressure.
This discharge pattern is particularly undesirable where both high pumping pressure levels and very high delivery volumes are involved. The resulting pulsations could, under such conditions, subject the discharge conduits to severe vibrational forces. Thus, the pumping unit would be subject to stress conditions which might cause failure.
A significant advance in hydraulically powered triplex pumps has been disclosed in U.S. Pat. No. 3,650,638, entitled "Hydraulically Powered Pump Having a Precompression Function" and issued to Clinton W. Cole on Mar. 21, 1972. This patent is assigned to the assignee of the present invention.